From: Hyun Kwon hyun.kwon@xilinx.com
stable inclusion from linux-4.19.207 commit ba7a035004e43d969f6a8fd1823ec87c4106d7cc
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commit de0a01f5296651d3a539f2d23d0db8f359483696 upstream.
Enable PCIe reference clock. There is no remove function that's why this should be enough for simple operation. Normally this clock is enabled by default by firmware but there are usecases where this clock should be enabled by driver itself. It is also good that PCIe clock is recorded in a clock framework.
Link: https://lore.kernel.org/r/ee6997a08fab582b1c6de05f8be184f3fe8d5357.162461810... Fixes: ab597d35ef11 ("PCI: xilinx-nwl: Add support for Xilinx NWL PCIe Host Controller") Signed-off-by: Hyun Kwon hyun.kwon@xilinx.com Signed-off-by: Bharat Kumar Gogada bharat.kumar.gogada@xilinx.com Signed-off-by: Michal Simek michal.simek@xilinx.com Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/pci/controller/pcie-xilinx-nwl.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/pci/controller/pcie-xilinx-nwl.c b/drivers/pci/controller/pcie-xilinx-nwl.c index 4850a1b8eec12..a86bd9660dae9 100644 --- a/drivers/pci/controller/pcie-xilinx-nwl.c +++ b/drivers/pci/controller/pcie-xilinx-nwl.c @@ -6,6 +6,7 @@ * (C) Copyright 2014 - 2015, Xilinx, Inc. */
+#include <linux/clk.h> #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/irq.h> @@ -169,6 +170,7 @@ struct nwl_pcie { u8 root_busno; struct nwl_msi msi; struct irq_domain *legacy_irq_domain; + struct clk *clk; raw_spinlock_t leg_mask_lock; };
@@ -849,6 +851,16 @@ static int nwl_pcie_probe(struct platform_device *pdev) return err; }
+ pcie->clk = devm_clk_get(dev, NULL); + if (IS_ERR(pcie->clk)) + return PTR_ERR(pcie->clk); + + err = clk_prepare_enable(pcie->clk); + if (err) { + dev_err(dev, "can't enable PCIe ref clock\n"); + return err; + } + err = nwl_pcie_bridge_init(pcie); if (err) { dev_err(dev, "HW Initialization failed\n");